Speed responsive switch



Oct. 14, 1958 c. H. BILL ET AL 2,856,478

SPEED RESPONSIVE SWITCH Filed Oct. 29, 1956 3 Sheets-Sheet 2 FIG. 5

F|G.8 FIG.7 FIG.9

INVENTOR. CHARLES a. mu. BYCHARLES w. nussea ATTORNEY Oct. 14, 1958 I c.H. BILL 'mL 2,856,478

SPEED RESPONSIVE SWITCH Filed Oct. 29, 1956 3 Sheets-Sheet 3 FIG. l2FIG. ll

FIG. l4

F G l3 INVENTOR. CHARLES H. BILL CHARLES w. MUSSER ATTORNEY limitedStates Patent SPEED RESPQNSIVE SWITCH (Iharles H. Bill, South Bend, Ind,and Charles W. Musser, Niles, Micln, assignors to Koontz-Wagner ElectricCo., Inc., South Bend, Ind, a corporation of Indiana Application October29, 1956, Serial No. 618,722

2 Claims. (Cl. 200-80) The present invention relates to switches andmore particularly speed responsive electrical switches.

One of the principal objects of the present invention is to provide ahighly reliable speed responsive electric switch which will withstandvibration and jarring without variation in its operation orresponsiveness to the speed of the rotating means being sensed.

Another object of the invention is to provide a speed responsive switchmechanism which can be accurately set to close or open an electricalcircuit and which can be readily adjusted in service to any desiredspeed within a wide range of settings.

Another object of the invention is to provide a sensitive speedresponsive electrical switch which is not affected in its operation orperformance by extraneous magnetic fields or by temperature and moisturechanges.

Still another object of the invention is to provide a sturdy relativelysimple speed responsive mechanism which can be readily adapted to a widevariety of applications and which can easily be serviced and maintainedin good working condition in the field.

A further object is to provide a speed responsive mechanism which can beused with a number of diiterent types of well known or conventionalelectrical switches to open or close a circuit when a predeterminedspeed is reached.

Additional objects and advantages will become apparent from thefollowing description with reference to the accompanying drawings,wherein:

Figure l is a longitudinal cross sectional view of our speed responsiveswitch mechanism, showing certain operative parts thereof in elevation;

Figure 2 is an end view of the switch mechanism with the cover removedto show the switch and switch actuating means;

Figure 3 is a cross sectional view of the fluid drive, showing the rotorand impeller in operative position;

Figure 4 is an end elevational view of the impeller of the fluid drive;

Figure 5 is a side elevational view of the impeller;

Figure 6 is a longitudinal cross sectional view of the impeller;

Figure 7 is an end elevational view of the rotor of the fluid drive;

Figure 8 is a side elevational view of the rotor;

Figure 9 is a longitudinal cross sectional view of the rotor;

Figures 10 and 11 are enlarged views of the switch actuating mechanismshowing it in the switch open and switch closed positions, respectively;

Figure 12 is an end view of the switch actuating cam;

Figure 13 is an elevational view of the switch actuating cam and aportion of the drive shaft therefor; and

Figure 14 is a cross sectional view of a microswitch.

Referring more specifically to the drawings and to Figure 1 inparticular, numeral designates the housing for the switch mechanism, 22a removable cover, 24 a fluid drive assembly, and 26 a conventionalmicroswitch connected to terminals 28 and 30 by lead wires 32 and 34,respectively. The base of housing 20 is provided with a flange 36 havinga plurality of holes for receiving bolts or studs for mounting theswitch mechanism on an engine or the like.

The fluid drive assembly 24 consists of a rotor 40 driven by a shaft 42journalled in ball bearings 44 and in the base of housing 20, and animpeller 50 for driving a shaft 52 journalled in ball bearings 54 and 56mounted in a bearing block 58. As seen in Figures 7, 8, and 9 the rotorhas a disc-shaped end plate 60 provided with four blades 62 andcontaining four fluid inlet ports 64 adjacent the inner ends of theblades. A hub 66 formed integrally with plate 60 is secured to shaft 42and for-ms a shoulder for engaging bearing 44, which together with ashoulder 68 formed on shaft 42 for engaging bearing 46 prevents end-playof said shaft and rotor. Bearings 44 and 46 are seated in a recess inthe base of the housing and are held in spaced relation by spacers 70and 72, all of said elements being held in said recess by a retainerring 74 secured to the base by a plurality of screws 76. Shaft 42, whichis sealed in a fluid tight relationship with the housing base by twosealing gaskets and 82 disposed in a recess in the end of the base,extends beyond the end of the base and is provided with a square endportion 84 for connecting the shaft to the rotating means to which theswitch is responsive.

As seen in Figures 4, 5 and 6, the impeller 50 consists of an end plateand a rim 92 forming a cup-shaped member containing a plurality ofequally spaced vanes 96 so arranged that when the rotor and impeller areassembled into operating position blades 62 will rotate freely in theconfines of the vanes but in close proximity therewith. A plurality offluid inlet holes 98 are provided adjacent the center of plate 90 and aplurality of fluid outlet holes 100 are provided in rim 92, one hole 100being provided adjacent the outer edge of each vane 96. A hub 102 formedintegrally with plate 90 is secured to shaft 52 and forms a shoulder forengaging bearing 56, which together with a shoulder 104 formed on shaft52 for engaging bearing 54 prevents end-play of said shaft and impeller.Bearings 54 and 56 are seated in a recess in bearing block 58 and heldin spaced relation by spacers 106 and 108, all of said elements beingheld in said recess by a retainer ring 110 secured to the block by aplurality of screws 112. Shaft 52 is sealed in a fluid tightrelationship with the block by a sealing gasket 114 disposed in a recessin the end of said block.

A fluid chamber is formed in the housing and is closed at the left handend, as viewed in Figure 1, by hearing block 58 which is sealed in fluidtight relationship with the inside walls of the housing by an O-ring 122in annular groove 124. The block is held in a fixed position in thehousing by a screw 126 extending through the wall of the housing intothe block. An opening 128 which contains a threadedplug 130 is providedin the side wall of the housing for filling chamber 120 with a suitablehydraulic fluid, such as, for example, D. C. Silicone Fluid, for use bythe fluid drive assembly in transmitting the rotative force from rotor40 to impeller 50.

Mounted on the end of shaft 52 and rotatable therewith is a cam whichoperates microswitch 26 through a cam follower member 144 pivoted to abracket 146 on the switch casing, and a stern 148 connected to one ofthe switch elements 149 (Figure 14), the circuit being closed whenelement 149 contacts element 149'. The microswitch 26 is rigidly securedto block 58 by one or more screws. For the purpose of the presentdescription the particular microswitch shown may be considered 3. as anyone of anurnber of well known microswitches readily available on themarket. These switches have a snap action and will open and close withrelatively small movement on the part of the actuating member. In theparticular embodiment shown in the drawings, the switch is closed bymovement of stem 148 inwardly toward the switch and thus, as seen inFigures 2 and 10, the cam being in its position farthest from theswitch, is in its switch open position, While, as seen in Figure 11, thecam being in its position closest to the switch, is in its switch closedposition. The cam is urged to its switch open position of Figures 2 andby a spring 150 connected at one end to a rod 152 joined to and movablewith earn 140 and at the other to a stationary post 154 mounted on andsecured to block 58. Post 154 and a second stationary post 156 mountedon and secured to block 58 form stops for rod 152 to limit the rotativemovement of cam 140.

, Cover 22 is sealed in fluid tight relation with the housing by anO-ring 160 and is held securely thereon by one. or more screws 162extending through the cover and the wall of the housing into block 58.

The rate of speed at which the microswitch will be closed can be changedto meet requirements by varying the strength of or tension on spring150. This can be done by merely selecting a spring of the desiredcalibration and substituting it for the one in the mechanism, or anadjustable anchor member of a well known construction can be used inplace of the stationary post 154. A coil spring may be used in place ofthe type shown in the drawings and the anchor point for one end of thecoil spring can be made adjustable. The rate of speed at which theswitch will close can also be changed by varying the amount of viscosityof the hydraulic fluid in chamber 120. However, in order to obtainconsistent operation of our switch mechanism, it is important to selectone'of a number of hydraulic fluids which have a substantially constantviscosity over extreme ranges of temperatures.

In the operation of our switch mechanism mounted on an engine or othermachine or apparatus, shaft 42 and rotor 40 are rotated in accordancewith the speed of the rotating member being sensed, impelling the fluidin chamber 120 through holes 64 in the rotor and holes 98 in theimpeller and then outwardly between blades 62 into vanes 96 of theimpeller. As long as the speed being sensed is below a preselected rateas determined by the strength of or tension on spring 150, impeller 50remains stationary and cam 140 and rod 152 remain in the position shownin Figures 2 and 10. As soon as the speed of the rotor increasessuificiently to cause the impeller to overcome the force of spring 150,cam 140 rotates in a clockwise direction as viewed in Figures 2, 10 and11 to the position shown in Figure 11. With the cam in this positionstem 148 of the microswitch is depressed toits closed switch positionand contacts 149 and 149 are pressed together and are held closed aslong as the speed of the rotor is suflicient to rotate the impeller andhold rod 152 against post 154. When the speed of the rotor decreases toa point below the predetermined .4 speed setting, spring 150 rotates camin the counter clockwise direction moving rod 152 from post 154 to post156, and permitting the microswitch to open, breaking the circuitcontrolled thereby.

A few modifications in our speed responsive switch have been suggestedhereinbefore. Further changes and modifications may be made withoutdeparting from the scope of the present invention.

We claim:

1. A speed responsive switch mechanism, comprising a housing having asealed fluid chamber, a disc shaped rotor in said chamber having bladesthereon and a plurality of holes spaced from the center thereof, a shaftconnected to said rotor and extending through one of the walls of saidchamber for driving said rotor, a cup shaped impeller in said chamberhaving holes in the periphery thereof and vanes thereon, fluid propelledby said rotor, said blades and vanes being disposed on facing surfacesof the rotor and impeller, respectively, a shaft connected to saidimpeller extending through the opposite wall of said chamber and beingadapted to be driven by said impeller, a cam operatively connected toand driven by said last mentioned shaft, a pin seated in said cam andprojecting radially outwardly, two spaced pins forming stops for saidfirst mentioned pin for limiting the rotation of movement of said cam, aspring connected to said first mentioned pin for resisting the rotationof said cam, electrical contact elements outside of said chamber, and ameans for operatively connecting one of said elements with said cam,whereby said contact elements are closed by the rotation of said carn.

2. A speed responsive switch mechanism, comprising a housing having asealed fluid chamber, a disc shaped rotor in said chamber having bladesthereon and a plurality of holes spaced from the center thereof, a shaftconnected to said rotor and extending through one of the walls of saidchamber for driving said rotor, a cup shaped impeller in said chamberhaving holes in the periphery thereof and vanes thereon, fluid propelledby said rotor,

a shaft connected to said impeller extending through the opposite wallof said chamber and being adapted to be driven by said impeller, a camoperatively connected to and driven by said last mentioned shaft, aspring for resisting the rotation of said cam, electrical contact elements outside of said chamber, and a means for operatively connectingone of said elements with said cam, whereby said contact elements areclosed by the rotation of said cam.

References Cited in the file of this patent UNITED STATES PATENTS933,367 De Dion et a1 Sept. 7, 1909 2,319,107 Brandt May 11, 19432,403,214 Fiddler July 2, 1946 2,668,043 Winterburn et al. Feb. 2, 19542,761,032 Thatcher Aug. 28, 1956 2,761,033 Thatcher Aug. 28, 19562,761,034 Gaylord et al Aug. 28, 1956 2,781,430 Thatcher Feb. 12, 1957

